First Author:   Takeshi Ebina School of Management, Tokyo University of Science ebina@ms.kuki.tus.ac.jp   500 Shimokiyoku Kuki, 346-8512, Japan   (81)-4-8021-7663(Phone) (81)-4-8021-7663(Fax) Second Author: Daisuke Shimizu Faculty of Economics, Gakushuin University daisuke.shimizu@gakushuin.ac.jp   1-5-1, Mejiro, Toshima-ku Tokyo, 171-8588, Japan   (81)-3-5992-3633(Phone)